Lewis Glinert, professor of linguistics at Dartmouth College in Hanover, N.H., and John Schommer of the University of Minnesota in Minneapolis examined Web sites dedicated to the 100 best-selling prescription drugs.

The researchers found consumers were expected to move in a maze of text and navigation choices and that content was unpredictable — including difficult to discern mixes of information and promotion.

“The Food and Drug Administration has rules about direct-to-consumer print and television drug advertising, so we think it makes sense to also regulate Web sites and other marketing tools when it comes to prescription medicine,” Glinert said in a statement.

“Consumers need consistent and balanced information.”

The findings were presented at the Communication, Medicine and Ethics Conference at Boston University School of Public Health.

Glinert noted the search engine Google has been working with the National Institutes of Health in Bethesda, Md., to improve Internet drug searches — including adding links to NIH content and risk data.

“Our research provides justification for Google’s move,” Glinert said. “Only time will tell if this is a major change for the better.”